1. Field of the Invention
The present invention relates in general to data transmission in mobile communications systems and more particularly card application toolkit support for Internet Protocol (IP) multimedia subsystems.
2. Description of the Related Art
In known wireless telecommunications systems, transmission equipment in a base station or access device transmits signals throughout a geographical region known as a cell. As technology has evolved, more advanced equipment has been introduced that can provide services that were not possible previously. This advanced equipment might include, for example, an E-UTRAN (evolved universal terrestrial radio access network) node B (eNB), a base station or other systems and devices. Such advanced or next generation equipment is often referred to as long-term evolution (LTE) equipment, and a packet-based network that uses such equipment is often referred to as an evolved packet system (EPS). An access device is any component, such as a traditional base station or an LTE eNB (Evolved Node B), that can provide a user agent (UA), such as user equipment (UE) or mobile equipment (ME), with access to other components in a telecommunications system.
In mobile communication systems such as an E-UTRAN, the access device provides radio accesses to one or more UAs. The access device comprises a packet scheduler for allocating uplink (UL) and downlink (DL) data transmission resources among all the UAs communicating to the access device. The functions of the scheduler include, among others, dividing the available air interface capacity between the UAs, deciding the resources (e.g. sub-carrier frequencies and timing) to be used for each UA's packet data transmission, and monitoring packet allocation and system load. The scheduler allocates physical layer resources for physical downlink shared channel (PDSCH) and physical uplink shared channel (PUSCH) data transmissions, and sends scheduling information to the UAs through a control channel. The UAs refer to the scheduling information for the timing, frequency, data block size, modulation and coding of uplink and downlink transmissions.
In certain mobile communication systems, there is a requirement for a universal integrated circuit card (UICC) application (e.g., a subscriber identity module (SIM), an Internet Protocol (IP) multimedia subsystem (IMS) SIM (ISIM), and a universal terrestrial radio access network (UTRAN) SIM (USIM)) may make use of Internet Protocol (IP) multimedia subsystem (IMS) functionalities controlled by mobile equipment (ME). See e.g., 3GPP TS 22.101. For example, FIG. 1, labeled Prior Art, shows a block diagram of an operation where a UICC application invites a peer to a session. FIG. 2, labeled Prior Art, shows an example of a UICC to IMS communication. In this example, an IMS UICC user initiated registration is performed where an IMS Subscriber Identity module (ISIM) is present.
It is possible that new UICC to ME command may include an open channel for IMS function which extends known Bearer Independent Protocol (BIP) commands for IMS like Close Channel, Send data, Receive data and Get Channel Status to allow the channel to use the IMS as a means to send and receive IMS traffic to and from the UICC.
In certain known systems (e.g., 3GPP 31.111 v.9.1) the UICC can use the Open Channel request to activate a PDP Context and to send IP data from the UICC to the network on an access point name (APN) chosen by the UICC. This function is in place under hospices of BIP that would allow for IP based over the air (OTA) updating of the UICC to replace the aging short message service (SMS) push and SMS transport currently in use.
This function takes the BIP feature further where the UICC is another IMS application and/or IMS communication service on the UE and as with other applications/communication services requires specific registration with the IMS service using an IMS application reference identifier/IMS communication service identifier (IARI/ICSI).
However, with this function, sending multiple registrations over session initiation protocol (SIP) can be costly for the mobile (e.g., in terms of battery life) and for the network (e.g., in terms of presenting unnecessary load). Additionally, unsolicited SIP messages pushed by the network can also have the same impact.
More specifically, if the a device is unaware of the IARI(s) hosted on the UICC at the time of the first registration of the device, the device will have to perform subsequent registrations when the UICC informs (at a later time) that the UICC wants the ME to initiate an IMS connection. The extra registrations can result in unnecessary and unwanted signaling. After boot up and after the SIP/IMS registration but before receiving the Open Channel command from the UICC; if the ME receives an incoming push message for an application (identified by an IARI) hosted on the UICC, the ME will simply discard any unsolicited messages from the IMS server.
Likewise, if the ME is unaware of the communication services (e.g., ICSI(s)) supported by applications contained within the UICC at the time of its first registration the ME will have to perform a subsequent registration later to support particular ICSI(s) contained in the UICC. The SIP REGISTER message contains media feature tags containing ICSI(s) along with IARI(s) values. For example, as shown in FIGS. 4 and 5 it would be desirable to provide enhanced support multiple IARI and ICSI values in the REGISTER and INVITE messages.